Proper handling and storage of brewing raw materials plays a crucial role in maintaining product quality and ensuring smooth brewery operations. Addressing potential quality issues promptly and effectively is equally important. Of all beer’s key ingredients, malt requires specific practices for receiving shipments, storing supplies, and responding to contamination incidents.

Malt shipments can arrive in various formats, each necessitating thorough inspection and preventive measures against contamination or physical damage. Contamination includes any unwanted biological, chemical, or physical presence in the malt or grain. Examples include pests, mold, hazardous materials from a previous truck shipment, and rocks and debris.

While many aspects are the same, every brewery operation has its unique differences that require special attention and protocols. This resource, developed by the Brewers Association (BA) Supply Chain Subcommittee, provides breweries of all sizes with a receiving template and best practice guidance. Additionally, it offers links to resources to help identify and inspect pests, so breweries can uphold their grain quality and maintain efficient brewing operations.

General Grain Receiving Guidelines

Use a Checklist

Malt and grains are received in different formats depending on the needs and size of a brewery. It may arrive as pallets of bags, as super sacks, or as a bulk malt truck delivery into a silo. At the time of delivery, the best practice is to perform an inspection that follows a pre-determined procedure and checklist. Download our checklist template to get started at your brewery.

Inspect Thoroughly

A bright light can be helpful to check for contaminants when performing an inspection. Rodent urine, for example, glows in ultraviolet (UV) light. Contaminants can be biological, physical, or chemical. Your brewery will need to determine its thresholds for mold, insects, physical damage, and other contaminants for acceptance and rejection purposes.

Document and Communicate

Keep the delivery driver on site through completion of the inspection. Do not let them leave until the inspection is complete and the paperwork is signed. If any issues are found during the intake inspection, take photos of both the damage/issue and pallet tags, make a note on the bill of lading (BOL), and then have the driver initial the BOL as an acknowledgement. If the issue identified with the product makes it unusable, reject the delivery and communicate with the supplier immediately.

It is good practice to have a conversation with your supplier before a rejection occurs. Other helpful touch points within the supply chain are visits to the transload facility and malt supplier’s production site. This gives insight into the overall process before grain arrives at your door.

Order Early

Finally, when possible, order far enough ahead so that, in case a shipment gets rejected, operations are not disrupted.

General Grain Storage Guidelines

Keeping contamination, which can easily spread under the right conditions, out of the production facility is imperative for contamination prevention. Good housekeeping and audits are also important to keep up on a regular basis.

Inspect and Maintain Cleanliness

• Regularly inspect for contaminants (e.g., bugs, dust)
• Use bug traps, pheromone monitors (dome, floor, probe/stick), and maintain a pest control program
• Clean floors, walls, and storage areas thoroughly from top to bottom
• Seal cracks in solid walls and floors, and keep the area free of dust and food items

Storage Environment

• Store malt in a clean, dry area away from heat and moisture
• Keep partial bags of milled grain in covered containers
• Ensure doors are closed and ventilation is screened to prevent pests

Storage Duration and Rotation

• Store whole-kernel malted products for up to 180 days max
• Store sensitive products (pre-milled, rolled, flaked, torrefied, puffed, un-malted grains) for up to 90 days max
• Use a cooler for sensitive products stored longer than 30 days in summer
• Rotate stock, inspect pallets and surrounding areas, and follow FIFO (First In, First Out)

Pest Control

• Understand that agricultural ingredients naturally contain some pests, but malting processes minimize them
• Employ a pest control company for routine checks

Good Manufacturing Practices (GMP)

• Store products at least 18 inches away from walls for easy inspection and cleaning
• Adhere to the BA’s Good Manufacturing Practices for Craft Brewers resource

Steps for Responding to Insect Contamination

Ideally, the receiving checklist and storage best practice measures are followed to the point that no contamination enters the building; however, in the event an issue occurs, there are steps you can take to help mitigate a larger issue. The steps below provide an initial structured response to insect grain contamination, emphasizing containment, cleaning, and collaboration with experts.

1. Isolate the Affected Malt: At the first sign of insect, weevil, or rodent activity, separate any infected malt immediately. Take it as far away from your other malts as possible. Place affected bags in garbage bags and quarantine them to prevent the spread of contamination.
2. Focus on Mitigation: Prioritize mitigation over assigning blame once the malt is received. Take immediate action to control and contain the issue.
3. Assess With Your Supplier: Contact your malt supplier for assistance in identifying the issue and determining the best response.
4. Implement Mitigation Measures:
   • Move the contaminated grain to cold storage to control insect contamination activity.
   • Surround the isolated pallet with traps to monitor and reduce pest presence.
   • Take the affected pallet to an outdoor area, de-stack it, and use an air wand or other method to blow off contaminants.
5. Clean Thoroughly: Perform a detailed cleaning of the entire grain storage area as soon as contamination is discovered. Conduct daily audits of the storage area following the initial cleaning to ensure ongoing control.
6. Engage Professional Pest Control: Contact your pest and insect control company for expert assessment and intervention. Prepare for potential fumigation or other required actions, depending on the severity of the infestation.
7. Establish and Monitor Thresholds: Set clear thresholds to measure whether the contamination is under control (e.g., zero live weevils). Monitor conditions and re-evaluate regularly.

Additional Resources on Common Grain Pests

• United States Department of Agriculture Stored Grain Insect Reference
• Canadian Grain Commission Insect Identification Keys
• United Kingdom Agriculture and Horticulture Development Board (AHDB) Insects and Mites in Stored Grain and Grain Stores resources